In semiconductor devices, a voltage withstanding structure is provided as a structure for improving the breakdown voltage in the peripheral region outside the active region. An example of the voltage withstanding structure is a RESURF structure. The RESURF structure includes e.g. an electrode layer extending from the active region to the peripheral region, and a high concentration region in contact with the electrode layer. In semiconductor devices, reduction of contact resistance at the contact with the electrode layer in the voltage withstanding structure is important in achieving stable breakdown voltage characteristics.